Speech enhancement technology can filter noise from received speech signals in order to enhance the speech signals. Speech enhancement technology can be applied to oral communication, voice user interface, voice input, and other applications. Currently, with rapid development of mobile devices, vehicle electronic devices, and robots, the requirements of oral communication, voice input, and human-machine voice user interface in the noisy environment are quickly increasing. Thus, the issues of how to filter noise, enhance speech signal, and increase the quality of oral communication and human-machine voice user interface has become more and more important.
Generally, the speech signals received from microphones include signals from voice sources and noise sources. Since noise sources decrease the quality of oral communication and human-machine voice user interface, it is essential to reduce noise in order to increase signal quality. Although traditional speech enhancement technology with a single microphone utilizes filters, adaptive filters, and statistical models to enhance signal quality, the efficiency of such technology is limited. In addition, although the speech enhancement system with multiple microphones has better efficiency than the speech enhancement system with a single microphone, the speech enhancement system with multiple microphones requires too much computation load to apply for mobile devices with limited computation capability.